Coed Darcy – How Green is the Valley Now?

Coed Darcy is one of the largest industrial regeneration projects in Europe. The site comprises over 1000 acres located on the former BP Llandarcy Oil refinery situated at the mouth of the Neath Valley and near Swansea, South Wales.  The site has a legacy of industrial impact within a sensitive environmental setting which creates a unique mix of multidisciplinary challenges over a seven-year program of reclamation, remediation and ecological enhancement to provide suitable development plots.  Reclamation and remediation to date has involved the use of multiple methodologies on a large scale efficiently and to budget while managing a broad range of petroleum hydrocarbon, solvent and metal contaminants in soil, ground and surface waters.

The location of the Crymlyn Bog, immediately adjacent the site and the former refinery waste disposal facility, presents a range of challenges requiring innovative solutions to the recovery of mobile free phase oil.  It is fed by a series of water-filled lagoons which were heavily impacted by over 80 years of refining activity. A key focus of the works has been to physically remove contamination from the water environment and to capture residual free phase hydrocarbons. Running parallel to the remediation works is a program of ecological enhancement which has included one of the largest ever Great Crested Newt trapping programmes, translocation of habitats, badger set relocation and creation of extensive new wetland and terrestrial habitat.

Four years into the reclamation and remediation program works have included 100km of redundant pipeline removal, 400,000 tonnes of soil bio-treatment, 1,000,000 litres of oil recovery from ground and 175,000m³ of recovery and treatment of hydrocarbon impacted sludge, yielding remarkable ecological enhancement especially of the water environment.   This case study provides a summary of the site works demonstrating  the interplay between geo-environmental engineering, hydrology, hydrogeology and ecology.